Since hepatocyte clearance, leading edge parencymal transit time and biliary excretion can be evaluated separately with hepatobiliary scan using Tc-99m-DISIDA, hepatobiliary scan may be useful in differentiating intrahepatic cholestasis from extrahepatic cholestasis. Excretory liver function was analysed in 13 healthy subjects and 11 patients with clinically suspected hepatocellular disease and 9 patients with extrahepatic biliary obstruction confirmed by surgery, radiological and clinical evidence. Indices of total liver activity (% TLA), liver parechymal uptake (% LPU), heart pool clearance (% HPC) and liver-heart rate (% LHR) were calculated from time activity curve over heart and liver. Compared with healthy subjects, significant reduction(p〈0.05) in total liver activity (% TLA) and liver-heart rate (% LHR) was observed in all patients group. But no useful indices was demonstrated in differentiating hepatocellular disease from extrahepatic biliary obstruction.